*{
	padding: 0;
	margin: 0;
}
li{
	list-style: none;
}
html{
	width: 100%;
	height: 100%;
}
body{
	width: 100%;
	height: 100%;
	overflow: hidden;
	background:url(./img/background.jpeg);
	background-size: 100% 100%;
}
.key-box{
	width: 672px;
	margin: 50px auto;
}
.key-box li{
	position: relative;
	float: left;
	width: 80px;
	height: 300px;
	border:2px solid black ;
	background: white;
	text-align: center;
	box-shadow: 10px 10px 20px black;
	
}
.key-box li span{
	position: absolute;
	right: -20px;
	background: #000;
	height: 150px;
	width: 40px;
	border-radius: 2px ;
	z-index: 1;
}
.music-box{
	width: 1200px;
	height: 600px;
	margin-left: -600px;
	left: 50%;
	position: absolute;
	z-index: -1;
	overflow: hidden;
}
.music-box li{
	position: relative;
	float: left;
	margin-left: 50px;
	top: 600px;
}
.music-box li img {
	width: 120px;
}
.music-box li.active{
	top: 0;
	opacity: 0.1;
	transition: all 3s;
}